bi_view_editor: window functions without ORDER BY clause do not have reliable behavior

bi_view_editor/models/bve_view.py

@@ -98,6 +98,19 @@ class BveView(models.Model):
         compute='_compute_users',
         store=True)
     query = fields.Text(compute='_compute_sql_query')
+    over_condition = fields.Text(
+        states={
+            'draft': [
+                ('readonly', False),
+            ],
+        },
+        readonly=True,
+        help="Condition to be inserted in the OVER part "
+             "of the ID's row_number function.\n"
+             "For instance, 'ORDER BY t1.id' would create "
+             "IDs ordered in the same way as t1's IDs; otherwise "
+             "IDs are assigned with no specific order.",
+    )
     er_diagram_image = fields.Binary(compute='_compute_er_diagram_image')
 
     _sql_constraints = [
@@ -285,11 +298,12 @@ class BveView(models.Model):
         self.env.cr.execute('CREATE or REPLACE VIEW %s as (%s)', (
             AsIs(view_name), AsIs(query), ))
 
-    @api.depends('line_ids', 'state')
+    @api.depends('line_ids', 'state', 'over_condition')
     def _compute_sql_query(self):
         for bve_view in self:
             tables_map = {}
-            select_str = '\n CAST(row_number() OVER () as integer) AS id'
+            select_str = '\n CAST(row_number() OVER ({}) as integer) AS id' \
+                .format(bve_view.over_condition or '')
             for line in bve_view.field_ids:
                 table = line.table_alias
                 select = line.field_id.name

bi_view_editor/readme/ROADMAP.rst

@@ -5,3 +5,4 @@
 * Data the user has no access to (e.g. in a multi company situation) can be
   viewed by making a view. Would be nice if models available to select when
   creating a view are limited to the ones that have intersecting groups.
+* Raise a warning in case the SQL query is not correct.

bi_view_editor/readme/USAGE.rst

@@ -21,3 +21,6 @@ To access the created BI View with a dedicated menu:
 A more advanced UI is also available under the "Details" tab. It provides extra
 possibilities for more advanced users, like to use LEFT JOIN instead of the
 default INNER JOIN.
+
+It also possible to improve the IDs generation for new views by adding an `Over Condition` in the "SQL" tab, see https://www.postgresql.org/docs/current/sql-expressions.html#SYNTAX-WINDOW-FUNCTIONS for further details.
+For instance, an ORDER BY clause helps preventing unreliable behavior when filtering the generated views.

bi_view_editor/views/bve_view.xml

@@ -85,8 +85,9 @@
                             </group>
                         </page>
                         <page string="SQL" groups="base.group_no_one">
+                            <field name="query"/>
                             <group>
-                                <field name="query" nolabel="1" />
+                                <field name="over_condition"/>
                             </group>
                         </page>
                         <page string="Security">